In my opinion, this is probably a good thing to keep in the back of your head. From what I have heard, the BMS program is not extremely well known like the BU MAMS program, and the Georgetown SMP program. But with BU MAMS, 30/150 get into their med school, and GT has 10/100 get in. Getting into CMS through BMS is your best shot, so try your hardest!
So I submitted my AMCAS probably in late June. I was under the impression that I would have to take a gap year between BMS and med school, since I thought this program worked like BU MAMS and the Georgetown SMP and my MCAT is terrible. It takes about a month for verification, so make sure to plan for that. I had friends submit their secondary to CMS in October. You can also update volunteering with a google form that CMS gives you in January.
I don't know about the matriculation rate to CMS dropping significantly, but what you are saying about the 70% who finished is correct. This year, going into the last quarter, we had around 70% of students who APPLIED TO CMS and who were STILL ENROLLED be "conditionally accepted." After speaking with the program director after final grades were posted, he said this number went to a little above 60%.
If you want to look at the raw numbers, here they are: Out of the 95 or so that started BMS this year, 85 finished the year and will be graduating with a masters in biomedical sciences.
These next numbers are rough estimates, not told to me by a BMS advisor or anything: I presume that out of the 85 that finished, around 70 were applying to CMS, and roughly 60% (this is a legit number told to me by an advisor) of the 70 students applying were accepted. Leaving about 40-45 of the original 95 students being accepted to CMS. The other 15 or so that finished the program and applied podiatry, PA, or pharmacy probably mostly got into their programs. So roughly 45/95 got into CMS, and lets say 12/95 got into other professional schools at RFUMS.
Students that left the program did so for 3 reasons. 1, they got in somewhere else. 2, they were getting failing grades/C's and the advisors told them the program is worthless for them. 3, they did something dumb and were asked to leave (I don't think this happened to anyone this year, but you never know).
All in all, these SMP's are a RISK, and for many people they are a shortcut to med school! You all need to know that when coming into it, and in my opinion this'll make you guys work even harder for that acceptance. BMS, just like the GT SMP, and BU MAMS is kind of a 45,000 dollar gamble, except with BMS, if you get one C and NEED to go to professional school next year, you can most likely get into the podiatry school or PA program, or pharmacy school. BU and GT do not offer these secondary options.
The reason why I call it a shortcut is because if I didn't do the program, I would have had to study all last year for the MCAT, take it, and then apply right now, and hopefully get into some sort of med school. I cut a whole year out of the process due to BMS, and am eternally grateful. As for my friends who didn't make it into CMS, they now need to start repaying their loans...
One last thing, don't get C's, but i'll tell you, it's better to get a C in the beginning of the program rather than the end. If you get a C in the beginning, you can still shoot for podiatry or PA or pharmacy, but if you get a C in neuro/physio at the end of the year, and you were banking on CMS, I think that the PA and Podiatry classes would have already been filled up by then, and you'd be stuck with nothing at the end of the year (unless you got accepted to some other school that's not RFU affiliated).